Austin26860

I recently bought a 2003 touring 350z and really not sure what oil they have In it right now. Just curious what you guys have used and what you think the best is. Should I use synthetic or conventional? Is synthetic really worth the extra money? The car has 120,000 miles. Thank you

dcains

iTrader: (15)

There's no "best" oil, but Nissan specifies a 5w-30. Any high-quality name brand will be fine, as long as you change it at the proper interval and use a good filter. So, having said that, I use Mobil 1 0w-40 with a Mobil 1 M1-110 filter, changed every 5k miles. If you ask 10 other Z owners, you'll get 10 other answers.

MicVelo

Well, nine other answers because I use exactly that combination as well. (Sometimes filter deviates but for the most part...)

dkmura

iTrader: (64)

Make it eight, as Mobil 1 0-40W has had good UOAs with my street and race Zs. OP- do a search and look for the Used Oil Analysis thread- lots of great info on different brands of oil and how they've performed in VQs.

dcains

iTrader: (15)

Great minds . . .

Maybe there will be 8 other guys not as smart or experienced as we, The Elders, are?

Seriously, though, I've been using M1 since it came in cardboard cans, maybe 1976 or '77?

rancor

Any 5W-30 will be fine but in general synthetics can last longer, tend to clean better, and do a little better in extreme heat. Pennzoil platnum and the new mobil 1 5W-30 are both good oils. I also use M1 0W-40 and a XG7317. The other fram filters are not good for the price but the ultras are actual a good value and arguably complete overkill for 5K intervals.

I wouldn't use any other 40 weight though as M1 is very close to a heavy 30 weight. Basically the car is hard on oil and tends to get 30 weights close to 20 weights over 5000 miles. The M1-0W40 gives a little more room to reduce the oil weight and allows the oil to get a little hotter before it becomes to thin. It is not needed if you don't drive the car hard.

Austin26860

So if I use Mobil 1 5w 30, should I use the m-110 oil filter? And if my car would happen to have been conventional this whole time, could switching to synthetic create any issues? Going from conventional to straight full synthetic?

dcains

iTrader: (15)

You shouldn't have any trouble switching to synthetic. The M1-110 filter is a bit larger than the OEM size, as is the M1-105 (and M1-108, too), but the Nissan filter is fine, too. At least around here, the local auto parts stores often have a special deal that includes 5 qts of Mobil 1 oil and a Mobil 1 filter for ~$35.

rancor

Switching wont cause any problems that weren't already there. So if you get a leak it just because the synthetic cleaned out some build up that was sealing you engine.

zakmartin

Use a good quality synthetic like Mobile-1. Most importantly, don't use a cheap, crappy Fram filter. Mobile-1 filters go great with Mobile-1 oil.

(I've had two Fram filters completely fail on me over the past 30 years, so I'm a bit biased in that regard.)

MicVelo

"The Elders". Hahahahahahahaha....

Not sure the other guys are quite up there yet but so far, what is it, like six or seven concurrences and I'm pretty sure none dems is elderly.

Yeah yeah..... "like us'ns."

EDIT: Whuups.... just noticed the time honored "Fram sucks" argument be a'brewin'. Heh heh.

dcains

iTrader: (15)

I should also mention, since we're spending your money, if the oil in the engine now looks particularly nasty/dirty, and you don't have service records, I might buy some cheap oil and a decent filter, and do a short-interval change to clean the crankcase. Just buy whatever regular 5w-30 and filter is on sale, run it for a few hundred miles, and then drain and pour in the Mobil 1 oil and filter. No point in contaminating the good oil, and then you'll be good for 5K miles or so.

Onkar02

I spoke with Rob Fuller of the ZCarGarage out here in San Jose and he recommended using a conventional 10w30 not fully synthetic, he said the Z's tend to consume a ton of oil and to try using a conventional oil over a full synthetic. I was using Royal Purple 5w30 full synthetic previously and burning tons of oil that's why he recommended it, just my two cents.

dcains

iTrader: (15)

A Z engine in proper repair shouldn't burn any appreciable amount of oil. FWIW, RP is crap, and should never be used in a Z motor, or even your lawn mower.

rancor

There is no reason to switch to a 10W-30, its thicker at startup than a 5W-30 which is worse for the engin and it's the same at operating temp. Yes you are in CA so it might not matter that much as you never get cold. Use some PP or M1 5W-30 to start or the M1 0W-40 if you want somthing a little thicker. Using conventional would also be fine.

Unless you have an 06 revup motor(you don't) the Z is not known for burning any oil unless it wasn't taken care of.

CptWiggles

Mobile 1 0W-40 with the Mobil 1 oil filter anywhere between 5-9k miles depending on driving conditions. If you do some research on the more technical aspects of motor oils, you'll likely come to the same conclusion that many of us seem to have arrived at. I use the same oil in every ICE I own besides 2 strokes.

MicVelo

Rob said that??? That's amusing because he's put oil in every one of my four Z cars and every time it's M1 0w-40 (and factory or MT-85 fluids for the rest.)

But yes, totally agree with Rancor. It almost doesn't matter what we use here in CA. 0w, 5w, 10w... it never gets cold enough to thin down to even 10w. (Additionally it rarely gets hot enough to thicken to 30 unless subject to "extreme" conditions - track work, long treks down through the central valley/Mojave/Death Valley in summer.

Lauriel680

Same here....Mobil 1 0w-40 with a Mobil 1 M1-110 filter

Onkar02

Yea, I gave him a call the other day after explaining an issue that I was having and he recommended switching out to what I mentioned earlier then giving him a call back once I put some miles on my car to go from there.

My car has over 200,000 miles on it but still runs great, it just had an oil consumption issue. At first there was a leak from my valve cover but got them both replaced along with the coil packs, and spark plugs and PCV valve. But, still having the issue of burning a lot of oil.

Id be open to trying the 0w-40 as well, well see what works! Thanks for the feedback.

Swaglife81

I'm gonna throw in a copy and paste from someone much smarter than I will ever be.

"Just base the first viscosity on your climate, e.g., 0W for northern Canada, 10W for Florida, and use the original oil spec for the operating weight. Most older cars work fine with 10W30."

So in simplest terms 5w is that all around weather type oil, nothing extreme on either end of the weather scale. Synthetic all the way or regular oil but change at faster intervals. Choose 30 or 40 depending on car mileage, wear and tear.